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skia/skia.git/ed0a9a175b53ee9792f2acdcafe4000f7d919aff/./gm/arcto.cpp
blob: 7eeceb9507489bc28ef174c6bd723fcd680be833 [file]
/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BD-style license that can be
* found in the LICENSE file.
*/
#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPathBuilder.h"
#include "include/core/SkPathEffect.h"
#include "include/core/SkPathMeasure.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/core/SkString.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkDashPathEffect.h"
#include "include/utils/SkParsePath.h"
#include "src/core/SkOSFile.h"
#include "src/core/SkRandom.h"
#include <stdio.h>
#include <array>
/* The test below generates a reference image using SVG. To compare the result for correctness,
enable the define below and then view the generated SVG in a browser.
*/
static constexpr bool GENERATE_SVG_REFERENCE = false;
/*
The arcto test below should draw the same as this SVG:
(Note that Skia's arcTo Direction parameter value is opposite SVG's sweep value, e.g. 0 / 1)
<svg width="500" height="600">
<path d="M 50,100 A50,50, 0,0,1, 150,200" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M100,100 A50,100, 0,0,1, 200,200" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M150,100 A50,50, 45,0,1, 250,200" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M200,100 A50,100, 45,0,1, 300,200" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M150,200 A50,50, 0,1,0, 150,300" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M200,200 A50,100, 0,1,0, 200,300" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M250,200 A50,50, 45,1,0, 250,300" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M300,200 A50,100, 45,1,0, 300,300" style="stroke:#660000; fill:none; stroke-width:2" />
<path d="M250,400 A120,80 0 0,0 250,500"
fill="none" stroke="red" stroke-width="5" />
<path d="M250,400 A120,80 0 1,1 250,500"
fill="none" stroke="green" stroke-width="5"/>
<path d="M250,400 A120,80 0 1,0 250,500"
fill="none" stroke="purple" stroke-width="5"/>
<path d="M250,400 A120,80 0 0,1 250,500"
fill="none" stroke="blue" stroke-width="5"/>
<path d="M100,100 A 0, 0 0 0,1 200,200"
fill="none" stroke="blue" stroke-width="5" stroke-linecap="round"/>
<path d="M200,100 A 80,80 0 0,1 200,100"
fill="none" stroke="blue" stroke-width="5" stroke-linecap="round"/>
</svg>
*/
DEF_SIMPLE_GM(arcto, canvas, 500, 600) {
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(2);
paint.setColor(0xFF660000);
// canvas->scale(2, 2); // for testing on retina
SkRect oval = SkRect::MakeXYWH(100, 100, 100, 100);
for (SkScalar angle = 0; angle <= 45; angle += 45) {
for (int oHeight = 2; oHeight >= 1; --oHeight) {
SkPathBuilder svgArc;
SkScalar ovalHeight = oval.height() / oHeight;
svgArc.moveTo(oval.fLeft, oval.fTop);
svgArc.arcTo({oval.width() / 2, ovalHeight}, angle, SkPathBuilder::kSmall_ArcSize,
SkPathDirection::kCW, {oval.right(), oval.bottom()});
canvas->drawPath(svgArc.detach(), paint);
svgArc.moveTo(oval.fLeft + 100, oval.fTop + 100);
svgArc.arcTo({oval.width() / 2, ovalHeight}, angle, SkPathBuilder::kLarge_ArcSize,
SkPathDirection::kCCW, {oval.right(), oval.bottom() + 100});
canvas->drawPath(svgArc.detach(), paint);
oval.offset(50, 0);
}
}
paint.setStrokeWidth(5);
const SkColor purple = 0xFF800080;
const SkColor darkgreen = 0xFF008000;
const auto colors = std::to_array<SkColor>({
SK_ColorRED,
darkgreen,
purple,
SK_ColorBLUE,
});
const char* arcstrs[] = {
"M250,400 A120,80 0 0,0 250,500",
"M250,400 A120,80 0 1,1 250,500",
"M250,400 A120,80 0 1,0 250,500",
"M250,400 A120,80 0 0,1 250,500"
};
int cIndex = 0;
for (const char* arcstr : arcstrs) {
if (auto path = SkParsePath::FromSVGString(arcstr)) {
paint.setColor(colors[cIndex++]);
canvas->drawPath(*path, paint);
}
}
// test that zero length arcs still draw round cap
paint.setStrokeCap(SkPaint::kRound_Cap);
SkPathBuilder path;
path.moveTo(100, 100)
.arcTo({0, 0}, 0, SkPathBuilder::kLarge_ArcSize, SkPathDirection::kCW, {200, 200});
canvas->drawPath(path.detach(), paint);
path.moveTo(200, 100)
.arcTo({80, 80}, 0, SkPathBuilder::kLarge_ArcSize, SkPathDirection::kCW, {200, 100});
canvas->drawPath(path.detach(), paint);
}
enum {
kParsePathTestDimension = 500
};
struct Legal {
char fSymbol;
int fScalars;
};
const auto gLegal = std::to_array<Legal>({
Legal{'M', 2},
Legal{'H', 1},
Legal{'V', 1},
Legal{'L', 2},
Legal{'Q', 4},
Legal{'T', 2},
Legal{'C', 6},
Legal{'S', 4},
Legal{'A', 4},
Legal{'Z', 0},
});
bool gEasy = false; // set to true while debugging to suppress unusual whitespace
// mostly do nothing, then bias towards spaces
static constexpr auto gWhiteSpace = std::to_array<char>({
0,
0,
0,
0,
0,
0,
0,
0,
' ',
' ',
' ',
' ',
0x09,
0x0D,
0x0A,
});
static void add_white(SkRandom* rand, SkString* atom) {
if (gEasy) {
atom->append(" ");
return;
}
int reps = rand->nextRangeU(0, 2);
for (int rep = 0; rep < reps; ++rep) {
int index = rand->nextRangeU(0, (int) std::size(gWhiteSpace) - 1);
if (gWhiteSpace[index]) {
atom->append(&gWhiteSpace[index], 1);
}
}
}
static void add_comma(SkRandom* rand, SkString* atom) {
if (gEasy) {
atom->append(",");
return;
}
size_t count = atom->size();
add_white(rand, atom);
if (rand->nextBool()) {
atom->append(",");
}
do {
add_white(rand, atom);
} while (count == atom->size());
}
static void add_some_white(SkRandom* rand, SkString* atom) {
size_t count = atom->size();
do {
add_white(rand, atom);
} while (count == atom->size());
}
static SkString make_random_svg_path(SkRandom* rand) {
SkString atom;
int legalIndex = rand->nextRangeU(0, (int) std::size(gLegal) - 1);
const Legal& legal = gLegal[legalIndex];
gEasy ? atom.append("\n") : add_white(rand, &atom);
char symbol = legal.fSymbol | (rand->nextBool() ? 0x20 : 0);
atom.append(&symbol, 1);
int reps = rand->nextRangeU(1, 3);
for (int rep = 0; rep < reps; ++rep) {
for (int index = 0; index < legal.fScalars; ++index) {
SkScalar coord = rand->nextRangeF(0, 100);
add_white(rand, &atom);
atom.appendScalar(coord);
if (rep < reps - 1 && index < legal.fScalars - 1) {
add_comma(rand, &atom);
} else {
add_some_white(rand, &atom);
}
if ('A' == legal.fSymbol && 1 == index) {
atom.appendScalar(rand->nextRangeF(-720, 720));
add_comma(rand, &atom);
atom.appendU32(rand->nextRangeU(0, 1));
add_comma(rand, &atom);
atom.appendU32(rand->nextRangeU(0, 1));
add_comma(rand, &atom);
}
}
}
return atom;
}
DEF_SIMPLE_GM(parsedpaths, canvas, kParsePathTestDimension, kParsePathTestDimension) {
SkString str;
FILE* file;
if (GENERATE_SVG_REFERENCE) {
file = sk_fopen("svgout.htm", kWrite_SkFILE_Flag);
str.printf("<svg width=\"%d\" height=\"%d\">\n", kParsePathTestDimension,
kParsePathTestDimension);
sk_fwrite(str.c_str(), str.size(), file);
}
SkRandom rand;
SkPaint paint;
paint.setAntiAlias(true);
for (int xStart = 0; xStart < kParsePathTestDimension; xStart += 100) {
canvas->save();
for (int yStart = 0; yStart < kParsePathTestDimension; yStart += 100) {
if (GENERATE_SVG_REFERENCE) {
str.printf("<g transform='translate(%d,%d) scale(%d,%d)'>\n", xStart, yStart,
1, 1);
sk_fwrite(str.c_str(), str.size(), file);
str.printf("<clipPath id='clip_%d_%d'>\n", xStart, yStart);
sk_fwrite(str.c_str(), str.size(), file);
str.printf("<rect width='100' height='100' x='0' y='0'></rect>\n");
sk_fwrite(str.c_str(), str.size(), file);
str.printf("</clipPath>\n");
sk_fwrite(str.c_str(), str.size(), file);
}
int count = 3;
do {
SkString spec;
uint32_t y = rand.nextRangeU(30, 70);
uint32_t x = rand.nextRangeU(30, 70);
spec.printf("M %u,%u\n", x, y);
for (uint32_t i = rand.nextRangeU(0, 10); i--; ) {
spec.append(make_random_svg_path(&rand));
}
auto path = SkParsePath::FromSVGString(spec.c_str());
SkAssertResult(path.has_value());
paint.setColor(rand.nextU());
canvas->save();
canvas->clipRect(SkRect::MakeIWH(100, 100));
canvas->drawPath(*path, paint);
canvas->restore();
if (GENERATE_SVG_REFERENCE) {
str.printf("<path d='\n");
sk_fwrite(str.c_str(), str.size(), file);
sk_fwrite(spec.c_str(), spec.size(), file);
str.printf("\n' fill='#%06x' fill-opacity='%g'", paint.getColor() & 0xFFFFFF,
paint.getAlpha() / 255.f);
sk_fwrite(str.c_str(), str.size(), file);
str.printf(" clip-path='url(#clip_%d_%d)'/>\n", xStart, yStart);
sk_fwrite(str.c_str(), str.size(), file);
}
} while (--count > 0);
if (GENERATE_SVG_REFERENCE) {
str.printf("</g>\n");
sk_fwrite(str.c_str(), str.size(), file);
}
canvas->translate(0, 100);
}
canvas->restore();
canvas->translate(100, 0);
}
if (GENERATE_SVG_REFERENCE) {
const char trailer[] = "</svg>\n";
sk_fwrite(trailer, sizeof(trailer) - 1, file);
sk_fclose(file);
}
}
DEF_SIMPLE_GM(bug593049, canvas, 300, 300) {
canvas->translate(111, 0);
SkPathBuilder p;
p.moveTo(-43.44464063610148f, 79.43535936389853f);
const SkScalar yOffset = 122.88f;
const SkScalar radius = 61.44f;
SkRect oval = SkRect::MakeXYWH(-radius, yOffset - radius, 2 * radius, 2 * radius);
p.arcTo(oval, 1.25f * 180, .5f * 180, false);
SkPaint paint;
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeCap(SkPaint::kRound_Cap);
paint.setStrokeWidth(15.36f);
canvas->drawPath(p.detach(), paint);
}
DEF_SIMPLE_GM(bug583299, canvas, 300, 300) {
const char* d="M60,60 A50,50 0 0 0 160,60 A50,50 0 0 0 60,60z";
SkPaint p;
p.setStyle(SkPaint::kStroke_Style);
p.setStrokeWidth(100);
p.setAntiAlias(true);
p.setColor(0xFF008200);
p.setStrokeCap(SkPaint::kSquare_Cap);
SkPath path = SkParsePath::FromSVGString(d).value_or(SkPath());
SkPathMeasure meas(path, false);
SkScalar length = meas.getLength();
SkScalar intervals[] = {0, length };
p.setPathEffect(SkDashPathEffect::Make(intervals, 0));
canvas->drawPath(path, p);
}